A friend just sent me a link to a Guardian article that describes a new program called "social impact bonds" that use private funds to address social problems, starting with reducing the rate at which short-term prisoners re-offend. See here:

Initial funds to back the first social impact bond in the program came partly from one of the Sainsbury Family Trusts. The Sainsbury family own one of the U.K.'s largest supermarkets, J. Sainsbury PLC. One family member, David Sainsbury, has a fortune worth $1.1 billion as of the Forbes 2010 World's Billionaires List. David Sainsbury served as U.K. Minister of Science & Innovation for 8 years until he resigned in 2006.

The Guardian article states that organizers should have early data on whether the programs being funded by the bonds are working within a year or so. The test will be how much of a reduction can be achieved in the rate at which prisoners re-offend within 12 months.